title: Intraoperative Transcranial Motor-Evoked Potential Monitoring of the Facial Nerve during Cerebellopontine Angle Tumor Resection.
abstract: Objective To determine whether transcranial motor-evoked potential (TCMEP) monitoring of the facial nerve (FN) during cerebellopontine angle (CPA) tumor resection can predict both immediate and long-term postoperative FN function. Design Retrospective review. Setting Tertiary referral center. Main Outcome Measures DeltaTCMEP (final-initial) and immediate and long-term facial nerve function using House Brackmann (HB) rating scale. Results Intraoperative TCMEP data and immediate and follow-up FN outcome are reported for 52 patients undergoing CPA tumor resection. Patients with unsatisfactory facial outcome (HB >2) at follow-up had an average deltaTCMEP of 57 V, whereas those with HB I or II had a mean deltaTCMEP of 0.04 V (t = -2.6, p < 0.05.) Intraoperative deltaTCMEP did not differ significantly between groups with satisfactory (HB I, II) and unsatisfactory (HB > 2) facial function in the immediate postoperative period. Conclusion Intraoperative TCMEP of the facial nerve can be a valuable adjunct to conventional facial nerve electromyography during resection of tumors at the CPA. Intraoperative deltaTCMEP >57 V may be worrisome for long-term recovery of satisfactory facial nerve function.
authors.affiliation: Departments of Otolaryngology, New York University School of Medicine, New York, New York, United States.
authors.forename: Maura K
authors.initials: MK
authors.lastname: Cosetti
authors.forename: Ming
authors.initials: M
authors.lastname: Xu
authors.forename: Andrew
authors.initials: A
authors.lastname: Rivera
authors.forename: Daniel
authors.initials: D
authors.lastname: Jethanamest
authors.forename: Maggie A
authors.initials: MA
authors.lastname: Kuhn
authors.forename: Aleksandar
authors.initials: A
authors.lastname: Beric
authors.forename: John G
authors.initials: JG
authors.lastname: Golfinos
authors.forename: J Thomas
authors.initials: JT
authors.lastname: Roland
keywords: cerebellopontine angle; facial nerve; intraoperative electrophysiologic monitoring; transcranial motor-evoked potential